
[Federal Register Volume 80, Number 101 (Wednesday, May 27, 2015)]
[Rules and Regulations]
[Pages 30132-30134]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-12698]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. FAA-2015-1819; Special Conditions No. 25-583-SC]


Special Conditions: Bombardier Aerospace, Models BD-500-1A10 and 
BD-500-1A11 Series Airplanes; Operation Without Normal Electrical Power

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final special conditions; request for comments.

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SUMMARY: These special conditions are issued for the Bombardier 
Aerospace Models BD-500-1A10 and BD-500-1A11 series airplanes. These 
airplanes will have novel or unusual design features when compared to 
the state of technology envisioned in the airworthiness standards for 
transport category airplanes. These design features are electrical and 
electronic systems that perform critical functions, the loss of which 
could be catastrophic to the airplane. The applicable airworthiness 
regulations do not contain adequate or appropriate safety standards for 
these design features. These special conditions contain the additional 
safety standards that the Administrator considers necessary to 
establish a level of safety equivalent to that established by the 
existing airworthiness standards.

DATES: This action is effective on Bombardier Aerospace on May 27, 
2015. We must receive your comments by June 26, 2015.

ADDRESSES: Send comments identified by docket number FAA-2015-1819 
using any of the following methods:
     Federal eRegulations Portal: Go to http://www.regulations.gov/ and follow the online instructions for sending 
your comments electronically.
     Mail: Send comments to Docket Operations, M-30, U.S. 
Department of Transportation (DOT), 1200 New Jersey Avenue SE., Room 
W12-140, West Building Ground Floor, Washington, DC 20590-0001.
     Hand Delivery or Courier: Take comments to Docket 
Operations in Room W12-140 of the West Building Ground Floor at 1200 
New Jersey Avenue SE., Washington, DC, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.
     Fax: Fax comments to Docket Operations at 202-493-2251.
    Privacy: The FAA will post all comments it receives, without 
change, to http://www.regulations.gov/, including any personal 
information the commenter provides. Using the search function of the 
docket Web site, anyone can find and read the electronic form of all 
comments received into any FAA docket, including the name of the 
individual sending the comment (or signing the comment for an 
association, business, labor union, etc.). DOT's complete Privacy Act 
Statement can be found in the Federal Register published on April 11, 
2000 (65 FR 19477-19478), as well as at http://DocketsInfo.dot.gov/.
    Docket: Background documents or comments received may be read at 
http://www.regulations.gov/ at any time. Follow the online instructions 
for accessing the docket or go to the Docket Operations in Room W12-140 
of the West Building Ground Floor at 1200 New Jersey Avenue SE., 
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Massoud Sadeghi, FAA, Airplane and 
Flight Crew Interface Branch, ANM-111, Transport Airplane Directorate, 
Aircraft Certification Service, 1601 Lind Avenue SW., Renton, 
Washington, 98057-3356; telephone 425-227-2117; facsimile 425-227-1149.

SUPPLEMENTARY INFORMATION: The FAA has determined that notice of, and 
opportunity for prior public comment on, these special conditions is 
impracticable because these procedures would significantly delay 
issuance of the design approval and thus delivery of the affected 
airplanes. In addition, the substance of these special conditions has 
been subject to the public comment process in several prior instances 
with no substantive comments received. The FAA therefore finds that 
good cause exists for making these special conditions effective upon 
publication in the Federal Register.

Comments Invited

    We invite interested people to take part in this rulemaking by 
sending written comments, data, or views. The most helpful comments 
reference a specific portion of the special conditions, explain the 
reason for any recommended change, and include supporting data.
    We will consider all comments we receive by the closing date for 
comments. We may change these special conditions based on the comments 
we receive.

Background

    On December 10, 2009, Bombardier Aerospace applied for a type 
certificate for their new Models BD-500-1A10 and BD-500-1A11 series 
airplanes (hereafter collectively referred to as ``CSeries''). The 
CSeries airplanes are swept-wing monoplanes with an aluminum alloy 
fuselage, sized for 5-abreast seating. Passenger capacity is designated 
as 110 for the Model BD-500-1A10 and 125 for the Model BD-500-1A11. 
Maximum takeoff weight is 131,000 pounds for the Model BD-500-1A10 and 
144,000 pounds for the Model BD-500-1A11. The CSeries airplanes will 
have an electronic flight control system.

Type Certification Basis

    Under the provisions of Title 14, Code of Federal Regulations (14 
CFR) 21.17, Bombardier Aerospace must show that the CSeries airplanes 
meet the applicable provisions of 14 CFR part 25 as amended by 
Amendments 25-1 through 25-129.
    If the Administrator finds that the applicable airworthiness 
regulations (i.e., 14 CFR part 25) do not contain adequate or 
appropriate safety standards for the CSeries airplanes because of a 
novel or unusual design feature, special conditions are prescribed 
under the provisions of Sec.  21.16.
    Special conditions are initially applicable to the model for which 
they are issued. Should the type certificate for that model be amended 
later to include any other model that incorporates the same or similar 
novel or unusual design feature, the special conditions would also 
apply to the other model.
    In addition to the applicable airworthiness regulations and special 
conditions, the CSeries airplanes must comply with the fuel vent and 
exhaust emission requirements of 14 CFR part 34 and the noise 
certification requirements of 14 CFR part 36, and the FAA must issue a 
finding of regulatory

[[Page 30133]]

adequacy under section 611 of Public Law 92-574, the ``Noise Control 
Act of 1972.''
    The FAA issues special conditions, as defined in 14 CFR 11.19, in 
accordance with Sec.  11.38, and they become part of the type-
certification basis under Sec.  21.17(a)(2).

Novel or Unusual Design Features

    The CSeries will incorporate the following novel or unusual design 
features: Electrical and electronic flight control systems that perform 
critical functions, the loss of which may result in loss of flight 
controls and other critical systems and may be catastrophic to the 
airplane.
    The applicable airworthiness regulations do not contain adequate or 
appropriate safety standards for these design features. These special 
conditions contain the additional safety standards that the 
Administrator considers necessary to establish a level of safety 
equivalent to that established by the existing airworthiness standards.

Discussion

    The CSeries airplanes have a fly-by-wire flight control system that 
requires a continuous source of electrical power in order to maintain 
an operable flight control system. Section 25.1351(d), Operation 
without normal electrical power, requires safe operation in visual 
flight rule (VFR) conditions for at least five minutes after loss of 
normal electrical power excluding the battery. This rule was structured 
around a traditional design using mechanical control cables and 
linkages for flight control. These manual controls allowed the crew to 
maintain aerodynamic control of the airplane for an indefinite period 
of time after loss of all electrical power. Under these conditions, a 
mechanical flight control system provided the crew with the ability to 
fly the airplane while attempting to identify the cause of the 
electrical failure, restart engine(s) if necessary, and attempt to re-
establish some of the electrical power generation capability.
    A critical assumption in Sec.  25.1351(d) is that the airplane is 
in VFR conditions at the time of the failure. This is not a valid 
assumption in today's airline operating environment where airplanes fly 
much of the time in instrument meteorological conditions on air traffic 
control defined flight paths. Another assumption in the existing rule 
is that the loss of all normal electrical power is the result of the 
loss of all engines. The five-minute period in the rule is to allow at 
least one engine to be restarted following an all-engine power loss in 
order to continue the flight to a safe landing. However, service 
experience on airplane models with similar electrical power-system 
architecture as the CSeries has shown that at least the temporary loss 
of all electrical power for causes other than all-engine failure is not 
extremely improbable. In addition, Bombardier is applying for extended 
operations (ETOPS) type design approval. In order to meet the 
applicable ETOPS requirements, the electrical power generation system 
must be able to power all of the electrically powered equipment 
required for a maximum-length ETOPS diversion.
    In order to maintain the same level of safety envisioned by the 
existing rule with traditional mechanical flight controls in a non-
ETOPS operating environment, the CSeries design must not be time-
limited in its operation under all reasonably foreseeable conditions, 
including loss of all normal sources of engine or auxiliary-power-unit 
(APU)-generated electrical power. Unless Bombardier can show that the 
non-restorable loss of the engine and APU power sources is extremely 
improbable, Bombardier must demonstrate that the airplanes can maintain 
safe flight and landing (including steering and braking on the ground 
for airplanes using steer/brake-by-wire and/or fly-by-wire speed brake 
panels) with the use of its emergency/alternate electrical power 
systems. These electrical power systems, or the minimum restorable 
electrical power sources, must be able to power loads that are 
essential for continued safe flight and landing, including those 
required for a maximum length ETOPS diversion.

Applicability

    As discussed above, these special conditions are applicable to the 
Model No. BD-500-1A10 and BD-500-1A11 series airplanes. Should 
Bombardier Aerospace apply at a later date for a change to the type 
certificate to include another model incorporating the same novel or 
unusual design feature, the special conditions would apply to that 
model as well.

Conclusion

    This action affects only certain novel or unusual design features 
on two model series of airplanes. It is not a rule of general 
applicability.
    The substance of these special conditions has been subjected to the 
notice and comment period in several prior instances and has been 
derived without substantive change from those previously issued. It is 
unlikely that prior public comment would result in a significant change 
from the substance contained herein. Therefore, the FAA has determined 
that prior public notice and comment are unnecessary and impracticable, 
and good cause exists for adopting these special conditions upon 
issuance. The FAA is requesting comments to allow interested persons to 
submit views that may not have been submitted in response to the prior 
opportunities for comment described above.

List of Subjects in 14 CFR Part 25

    Aircraft, Aviation safety, Reporting and recordkeeping 
requirements.

    The authority citation for these special conditions is as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701, 44702, 44704.

The Special Conditions

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the following special conditions are issued as part of 
the type certification basis for Bombardier BD-500-1A10 and BD-500-1A11 
series airplanes.

Operation Without Normal Electrical Power

    In lieu of Title 14 Code of Federal Regulations (14 CFR) 25.1351(d) 
the following special conditions apply:
    1. Bombardier must show by test or a combination of test and 
analysis that the airplane is capable of continued safe flight and 
landing with all normal electrical power sources inoperative, as 
prescribed by paragraphs 1a and 1b below. For purposes of these special 
conditions, normal sources of electrical power generation do not 
include any alternate power sources such as the battery, ram air 
turbine, or independent power systems such as the flight-control 
permanent magnet generating system. In showing capability for continued 
safe flight and landing, Bombardier must account for systems 
capability, effects on crew workload and operating conditions, and the 
physiological needs of the flightcrew and passengers for the longest 
diversion time for which Bombardier is seeking approval.
    a. In showing compliance with this requirement, Bombardier must 
account for common-cause failures, cascading failures, and zonal 
physical threats.
    b. Bombardier may consider the ability to restore operation of 
portions of the electrical power generation and distribution system if 
it can be shown that unrecoverable loss of those portions of the system 
is extremely improbable. The design must provide an alternative source 
of electrical power for the time required to restore the minimum 
electrical power generation capability

[[Page 30134]]

required for safe flight and landing. Bombardier may exclude 
unrecoverable loss of all engines when showing compliance with this 
requirement.
    2. Regardless of any electrical generation and distribution system 
recovery capability shown under paragraph 1 of these special 
conditions, sufficient electrical system capability must be provided 
to:
    a. Allow time to descend, with all engines inoperative, at the 
speed that provides the best glide distance, from the maximum operating 
altitude to the top of the engine restart envelope, and
    b. Subsequently allow multiple start attempts of the engines and 
auxiliary power unit (APU). The design must provide this capability in 
addition to the electrical capability required by existing part 25 
requirements related to operation with all engines inoperative.
    3. The airplane emergency electrical power system must be designed 
to supply:
    a. Electrical power required for immediate safety, which must 
continue to operate without the need for crew action following the loss 
of the normal electrical power, for a duration sufficient to allow 
reconfiguration to provide a non-time-limited source of electrical 
power.
    b. Electrical power required for continued safe flight and landing 
for the maximum diversion time.
    4. If Bombardier uses APU-generated electrical power to satisfy the 
requirements of these special conditions, and if reaching a suitable 
runway for landing is beyond the capacity of the battery systems, then 
the APU must be able to be started under any foreseeable flight 
condition prior to the depletion of the battery or the restoration of 
normal electrical power, whichever occurs first. Flight test must 
demonstrate this capability at the most critical condition.
    a. Bombardier must show that the APU will provide adequate 
electrical power for continued safe flight and landing.
    b. The operating limitations section of the airplane flight manual 
(AFM) must incorporate non-normal procedures that direct the pilot to 
take appropriate actions to activate the APU after loss of normal 
engine-driven generated electrical power.
    5. As part of showing compliance with these special conditions, the 
tests to demonstrate loss of all normal electrical power must also take 
into account the following:
    a. The assumption that the failure condition occurs during night 
instrument meteorological conditions (IMC) at the most critical phase 
of the flight, relative to the worst possible electrical power 
distribution and equipment-loads-demand condition.
    b. After the un-restorable loss of normal engine generator power, 
the airplane engine restart capability is provided and operations 
continued in IMC.
    c. The airplane is demonstrated to be capable of continued safe 
flight and landing. The length of time must be computed based on the 
maximum diversion time capability for which the airplane is being 
certified. Bombardier must account for airspeed reductions resulting 
from the associated failure or failures.
    d. The airplane must provide adequate indication of loss of normal 
electrical power to direct the pilot to the non-normal procedures, and 
the operating limitations section of the AFM must incorporate non-
normal procedures that will direct the pilot to take appropriate 
actions.

    Issued in Renton, Washington, on May 15, 2015.
Michael Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 2015-12698 Filed 5-26-15; 8:45 am]
 BILLING CODE 4910-13-P


